From 1b21b68ac1380869915e3f084117cc394cc49f7e Mon Sep 17 00:00:00 2001
From: p-x9 <50244599+p-x9@users.noreply.github.com>
Date: Thu, 13 Jun 2024 15:09:46 +0900
Subject: [PATCH] Refactor null terminated string reading

---
 Sources/MachOKit/Extension/UnsafePointer+.swift | 9 +++++++++
 Sources/MachOKit/MachOFile+Strings.swift        | 9 +++------
 Sources/MachOKit/MachOImage+Strings.swift       | 5 ++---
 3 files changed, 14 insertions(+), 9 deletions(-)

diff --git a/Sources/MachOKit/Extension/UnsafePointer+.swift b/Sources/MachOKit/Extension/UnsafePointer+.swift
index fd0cb11..61ed842 100644
--- a/Sources/MachOKit/Extension/UnsafePointer+.swift
+++ b/Sources/MachOKit/Extension/UnsafePointer+.swift
@@ -62,3 +62,12 @@ extension UnsafePointer<UInt8> {
         return (string, offset)
     }
 }
+
+extension UnsafePointer<CChar> {
+    func readString() -> (String, Int) {
+        let offset = Int(bitPattern: strchr(self, 0)) + 1 - Int(bitPattern: self)
+        let string = String(cString: self)
+
+        return (string, offset)
+    }
+}
diff --git a/Sources/MachOKit/MachOFile+Strings.swift b/Sources/MachOKit/MachOFile+Strings.swift
index 5013e3c..946e075 100644
--- a/Sources/MachOKit/MachOFile+Strings.swift
+++ b/Sources/MachOKit/MachOFile+Strings.swift
@@ -60,15 +60,12 @@ extension MachOFile.Strings {
 
                 let ptr = baseAddress
                     .advanced(by: nextOffset)
-                    .assumingMemoryBound(to: CChar.self)
-                let string = String(cString: ptr)
-
-                let nextPointer = UnsafePointer(strchr(ptr, 0))
-                    .advanced(by: 1)
+                    .assumingMemoryBound(to: UInt8.self)
+                let (string, offset) = ptr.readString()
 
                 let result = Element(string: string, offset: nextOffset)
 
-                nextOffset += Int(bitPattern: nextPointer) - Int(bitPattern: ptr)
+                nextOffset += offset
 
                 return  result
             }
diff --git a/Sources/MachOKit/MachOImage+Strings.swift b/Sources/MachOKit/MachOImage+Strings.swift
index 6a28caf..93a9bdc 100644
--- a/Sources/MachOKit/MachOImage+Strings.swift
+++ b/Sources/MachOKit/MachOImage+Strings.swift
@@ -72,9 +72,8 @@ extension MachOImage.Strings {
             if offset >= tableSize {
                 return nil
             }
-            let string = String(cString: nextPointer)
-            nextPointer = UnsafePointer(strchr(nextPointer, 0))
-                .advanced(by: 1)
+            let (string, nextOffset) = nextPointer.readString()
+            nextPointer = nextPointer.advanced(by: nextOffset)
 
             return .init(string: string, offset: offset)
         }